This relates generally to drilling oil and gas wells in artic regions.
Oil and gas deposits have been located in regions which would be generally covered by ice throughout the year. In order to drill in such areas, a drilling ship must be led through the ice by an ice breaker. In addition, a second drilling ship maybe desirable on site in order to drill a relief well if a blowout or other failure occurs. Commonly, the second drilling ship maybe accompanied by its own separate ice breaker. Thus, a convoy of four ships may be needed.
Such a convoy is highly expensive since each of the drilling ships demands extremely high hourly rates and is very expensive to operate. Moreover, the second drilling ship may never even be needed and simply is on site in a standby mode in case of emergency.